Systems and methods for measuring bearing endplay

ABSTRACT

A system for use in measuring an end play of a wheel hub assembly includes a structure attachable to a shaft of a wheel hub assembly. A frame has a cavity receiving a measurement probe extending outwardly from the cavity. The probe contacts the structure and is configured to measure movement of the structure to determine endplay of the bearing assembly on the shaft. The frame includes a plurality of legs extending from the frame to a hub mounted on the shaft and coupled to the bearing to support the frame relative to the hub. The handle is connected to the frame and extends substantially perpendicularly relative to an axis of the shaft and extends to opposite sides of the axis. The frame, the plurality of legs and the handle are sufficiently rigid to allow a user to apply a force to the handle to move the hub in an axial direction relative to the shaft until cessation of movement of the hub relative to the shaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 12/951,727 filed onNov. 22, 2010, titled “Systems and Methods for Measuring BearingEndplay”, and published as U.S. Publication No. 2012-0079892-A1 on Apr.5, 2012.

This application relates to U.S. application Ser. No. 12/492,826, filedJun. 26, 2009, titled “Systems And Methods For Preloading A Bearing AndAligning A Lock Nut” (Attorney Docket No, 0545.057), U.S. applicationSer. No. 11/341,948, filed Jan. 27, 2006, and titled “Method AndApparatus For Preloading A Bearing,” published as U.S. Publication No.US2007/0177829A1 on Aug. 2, 2007 (Attorney Docket No. 0545.049), U.S.application Ser. No. 11/354,513, filed Feb. 15, 2006, and titled“Method, Apparatus, and Nut for Preloading a Bearing”, issued as U.S.Pat. No. 7,389,579 on Jun. 24, 2008 (Attorney Docket No. 0545.051), andU.S. Provisional Application No. 61/388,806, filed Oct. 1, 2010, andtitled “Systems and Methods for Preloading a Bearing and Aligning LockNut” (Attorney Docket No. 0545.069P), each of which is incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates, generally, to methods and apparatus forpreloading antifriction bearings in drive trains, particularly, topreloading and adjusting bearings while monitoring the preload beingapplied.

BACKGROUND OF THE INVENTION

Various means have been devised to simplify the adjustment of axlebearings, specifically, truck axle bearings. It is generally acceptedthat in some bearing installations, for example, axle bearings, the lifeof the bearing will be optimized if the adjustment is made for a slightaxial compressive deflection, for example, about 0.003 inches (wherethis amount is the compressive deflection of the two bearings combined),which is often referred to as “a three thousandths preload.” Typicalprior art methods of creating these preloads are obtained by applyingspecified torques to the bearing assembly, for example, by tighteningthe nut that retains the bearings. However, for several reasons, it istypically extremely difficult to achieve such preload settings underactual in-field conditions, such as in a mechanic shop. For example, theassembly of a heavy truck wheel onto a wheel hub assembly is arelatively cumbersome procedure that hinders the mechanic. Moreover, thewheel hub assembly always includes at least one inner seal, usually alip type of seal, which can impose a resistive drag torque component tothe preload torque, particularly when the seal is new.

In one example, a user may tighten a nut holding a bearing on a shaft toa particular torque and then such nut may be loosened to a particularposition by referencing an index mark on a face of the nut a particulardistance. Such a nut could be turned a particular portion of a rotationby referencing such a marking, e.g., half a turn. Such an adjustment isa particularly inexact procedure given that wheel nut adjustment isdesired to have precision of 0.001 of an inch while the degree ofrotation of a nut as described is relatively inexact.

Lock nut systems using a single nut are often utilized to retain a wheelor hub assembly, including axle bearings, on a shaft. Such lock nutsystems may be connected to a shaft and inhibit rotation of a retainingnut relative to such shafts. For example, such systems are oftenutilized on motor vehicles, such as axles and wheel ends. Typically, alock nut will be engageable with a locking member or keeper whichinhibits movement of the nut relative to the shaft. The locking membermay include a protruding portion which extends into a slot or receivingportion of a shaft. The locking member may also engage the nut such thatthere is little or no movement between the nut and shaft.

Thus, a need exists for providing accurate and repeatable procedures anddevices for providing and adjusting bearing preload and for adjustinglock nut systems configured to retain preloaded bearings.

SUMMARY OF THE INVENTION

The present provides, in a first aspect, a system for use in measuringan end play of a bearing of a wheel hub assembly which includes a capattachable to an end of a shaft of the wheel hub assembly. A frame has acavity receiving a measurement probe extending outwardly from thecavity. The probe contacts the cap and is configured to measure movementof the cap relative to the wheel hub to determine endplay of a bearingof the hub assembly on the shaft. The frame includes a plurality of legsextending from the frame to a hub mounted on the shaft and coupled tothe bearing to support the frame relative to the hub. The handle isconnected to the frame and extends substantially perpendicularlyrelative to an axis of the shaft and extends to opposite sides of theaxis. The frame, the plurality of legs and the handle are sufficientlyrigid to allow a user to apply a force to the handle to move the hub inan axial direction relative to the shall until cessation of movement ofthe hub relative to the shaft.

The present invention provides, in a second aspect, a method fordetermining an endplay of a bearing of a wheel hub assembly mounted on ashaft which includes attaching a cap to an end of the shaft. A pluralityof legs of an endplay measuring apparatus is connected to a hub of thehub assembly mounted on the shaft. A measuring probe is received in acavity of a frame of the apparatus. The probe outwardly extends from thecavity to contact the cap. A force is applied to a handle of theapparatus connected to the frame and the plurality of legs to move thehub in a first axial direction until a cessation of movement of the hub.The handle extends substantially perpendicularly relative to an axis ofthe shaft and extends to opposite sides of the axis. A first measurementof the probe is determined. A force is applied on the handle in a secondaxial direction opposite to the first axial direction until a secondcessation of movement of the hub. A second measurement of the probe isdetermined after the second cessation of movement. A movement of the capby the probe is determined to determine an endplay of the bearing bycomparing the first measurement to the second measurement.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention will be readily understood from thefollowing detailed description of aspects of the invention taken inconjunction with the accompanying drawings in which:

FIG. 1 is perspective view of a system for measuring endplay on abearing of a wheel hub assembly mounted on a shaft in accordance withthe present invention;

FIG. 2 is a side cross-sectional view of another embodiment of a systemfor measuring endplay on a bearing of a wheel hub assembly mounted on ashaft in accordance with the present invention; and

FIG. 3 is a perspective view of the system of claim 2 mounted on awheel.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the principals of the present invention, systems andmethods for adjusting bearings mounted on a shaft are provided. In anexemplary embodiment depicted in FIG. 1, a system 10 for measuring endplay is mounted on a wheel hub assembly 20.

Wheel hub assembly 20 is an assembly that would typically be found on afront or rear axle of a cab or tractor of a tractor-trailer, or an axleof a trailer. However, aspects of the invention are not limited to usefor vehicle bearings. As will generally be understood by those skilledin the art, aspects of the invention may be used to service bearings andbearing assemblies in any machine or device that employs bearings,including, but not limited to: power trains, transmissions, machinecomponents, on and off-road vehicles, aircraft wheels, marine drives,spacecraft, conveyor rolls, and windmills, among others. According toaspects of the present invention, system 10 may be used in these and anyother assembly for which bearing preload and/or endplay is desired, forexample, any assembly that utilizes thrust and radial load carryingbearings that are indirectly mounted.

As shown in FIGS. 1-2, for example, wheel hub assembly 20 includes awheel hub or, simply, a hub 12, a threaded, spindle, axle, or a shaft14. As is typical, shaft 14 is mounted on two antifriction bearings andshaft 14 includes an exposed end 13, which is typically threaded on theoutside diameter and is partially hollow at the end. A retaining nut 11(FIG. 3) may be threaded to exposed end 13 to retain hub 12 thereon.

As shown in FIG. 2, as is typical of bearings, outboard bearing 16includes an inner race (or cone) 15, an outer race (or cup) 17, aplurality of rollers 22, and a roller cage 24. Similarly, an inboardbearing (not shown) includes an inner race (or cone) (not shown), anouter race (or cup) (not shown), a plurality of rollers (not shown), androller cage (not shown). The details of an inboard bearing and anoutboard bearing are described and depicted in co-owned U.S. Pat. No.7,303,367, issued Dec. 4, 2007 (application Ser. No. 11/029,531 filedJan. 5, 2005), entitled “Lock Nut System”; U.S. Publication No.2007/0177829A1, published Aug. 2, 2007, (application Ser. No. 11/341,948filed Jan. 27, 2006), entitled “Method and Apparatus for Preloading aBearing”; and U.S. Pat. No. 7,389,579, issued Jun. 24, 2008 (applicationSer. No. 11/354,513, filed Feb. 15, 2006), entitled “Method, Apparatus,and Nut for Preloading a Bearing”, the entirety of which areincorporated herein by reference.

As depicted in FIGS. 5-8 of co-owned U.S. Provisional Application No.61/388,806, filed Oct. 1, 2010, entitled “Systems and Methods forPreloading a Bearing and Aligning Lock Nut” (Attorney Docket No.0545.069P), for example, retaining nut 11 may be a locking nut asdisclosed in co-owned U.S. Pat. No. 7,303,367 (application Ser. No.11/029,531 filed Jan. 5, 2005), entitled “Lock Nut System”; U.S.Publication No. 2007/0177829A1 (application Ser. No. 11/341,948 filedJan. 27, 2006), entitled “Method and Apparatus for Preloading aBearing”; and U.S. Patent No. 7,389,579 (application Ser. No.11/354,513, filed Feb. 15, 2006), entitled “Method, Apparatus, and Nutfor Preloading a Bearing”, In another example, a retaining nut could bea locking nut as disclosed in U.S. Pat. No. 3,762,455 to Anderson Jr. Inthe conventional art, retaining nut 11 typically is used to secure awheel (e.g., wheel 200, FIG. 3) or hub assembly to non-rotating axle orspindle 14. However, in aspects of the present invention, retaining nut11 may be useful in varying the preload and/or endplay of bearing 16.Bearing 16 may be a tapered roller bearing, or aspects of the inventionmay be applied to other types of antifriction bearings for which it isdesirable to provide preload and/or endplay, hr example, sphericalroller bearings, deep groove ball bearings, and the like.

As described above, it is desirable for a adjustment to be provided to abearing assembly such that a desired amount of endplay is present. Afterretaining nut 11 is tightened on the shaft to a particular predeterminedtorque (e.g., using a torque wrench), the standard procedures call for aloosening of say ¼ turn to create a desirable endplay of bearing 16 onshaft 14. All typical adjustment procedures require that said endplay bemeasured with a dial indicator to assure a safe adjustment had beenachieved.

System 10 may include a frame 30 formed of the plurality of crossmembers 35. Frame 30 may be connected to a handle 40 at one end ofsystem 10 by connecting legs 45. Frame 30 may also be connected topressing legs 50 which may extend from frame 30 away from handle 40 andto wheel hub 12 as depicted in the figures. Pressing legs 50 may beconnected to wheel hub 12 at wheel lugs 60. Connecting tabs 55 may beconnected to, or monolithic relative to, pressing legs 50 and may bealigned in a direction substantially perpendicular to pressing legs 50,such that connecting tabs 55 may be received under lug nuts 70 threadedonto wheel lugs 60. Pressing legs 50 may be substantially parallel toeach other and may be connected to wheel hub 12 such that the legs aresubstantially parallel to the axis (i.e., longitudinal axis) of shaft14. Connecting legs 45 may also be substantially parallel to the axis ofshaft 14. Each connecting leg and pressing leg on a same side of frame30 may be monolithic to, or connected to, one another. The cross members(i.e., cross members 35) may be connected on each side thereof to atleast one of pressing legs 50 and connecting legs 45.

A spindle adapter or cap 80 May be threaded onto end 13 of shaft 14 suchthat cap 80 is tightened to a particular torque, for example. Cap 80 mayinclude a wrenching surface to allow such tightening. As used herein,cap refers to any structure, or part of a structure, which is affixed tothe threaded end 13 of shaft 14. A dial indicator or probe 90 may bereceived in a cavity 95 of frame 30 such that probe 90 is stationaryrelative to frame 30 and a remainder of system 10. For example, probe 90may be connected to cross members 35 in any number of ways, such as bywelding or by mechanical fasteners. Frame 30 may include an opening 32to allow user to view a display 34 of a dial indicator of probe 90.

A probe tip 100 of a probe stem 99 may contact a cap 80 (e.g., anaxially projecting portion 82) when cap 80 is threaded onto shaft 14.Probe tip 100 may be aligned in a direction substantially parallel to anaxis of shaft 14. For example, an axis of probe tip 100 may besubstantially aligned with the longitudinal axis of shaft 14.

When a measurement of endplay of hub assembly 20, including wheel hub 12and bearing 16, is desired, a user may grasp handle 40 and push in afirst direction toward hub 12. until no further forward motion occurs.Probe 90 may then be reset to a known setting (e.g., ‘zeroed’) to allowa measurement by probe 90 which it is in contact with cap 80. The usermay then pull in a second direction on handle 40 until no furtherreverse motion of hub 12 occurs. The user may then view display 34 todetermine a measurement of the movement of hub 12 relative to the cap asdetermined by the movement of probe 90 which is in contact with the faceof the cap. The movement by the probe signals a distance on the displaywhich indicates the endplay of wheel hub 12 and bearing 16. Thedifference between a movement after forward motion of the hub ceases tothat after reverse motion of the hub ceases provides an indication ofthe endplay of bearing 16. The components of system 10 (e.g., theconnecting legs, extending legs, handle, tabs, and frame) may besufficiently rigid to allow the application of a force (e.g., in aforward and reverse axial direction relative to shaft 14) to handle 40to transfer such force to hub 12 to allow the motion of hub 12 in aforward and reverse direction to allow the measurement of the endplay asdescribed.

Further, as described above probe 90 is connected to frame 30. Theconnection of probe 90 to frame 30 may be fixed as described above orcould be adjustable. For example, probe 90 may be connected to a plate33 which has screws or other connectors received in slots of frame 35such that probe 90 may be adjusted to a particular position andtightened by the screws or fasteners to frame 35 if further adjustmentis desired other than the use of cap extender 85 described above.

After the measurement of endplay described above (or prior thereto) itmay be desirable to tighten nut 11 to adjust such endplay. As depictedin FIG. 1, openings 52 may be present between connecting legs 50 onopposite sides of system 10. A user may insert a wrench 5 into one ofopenings 52 to engage the wrench with a nut 11 to adjust an endplay ofbearing 16 and hub 12.

As described above and depicted in FIG. 1, endplay may be measured bysystem 10 with tabs 55 placed on wheel hub 12 and held in place by wheellugs 60. In another example depicted in FIG. 3, tabs 55 may be receivedon top of wheel 200 connected to hub 12. Tabs 55 may be connected towheel 200 by top lugs 72 holding tabs 55 on top of lug nuts 70 andbetween top lug nuts 72 and lug nuts 70. FIG. 2 is a cross-sectionalview of the example depicted in FIG. 3 with the wheel (i.e., wheel 200)removed for simplicity.

As depicted in FIGS. 2-3, an extension 82 of cap 80 may be received in acap extender 85 such that cap extender 85 may be received between cap 80and probe 90. Extension 82 may be longitudinally aligned relative to theaxis of shaft 14. Extension 82 may have a longitudinal dimensionsubstantially equal to the axial thickness (relative to the axis ofshaft 14) of wheel 200 and lug nuts 70. The sole difference between theexamples depicted in FIG. 1 and FIG. 3 are the connection tabs 55 on topof wheel 200 and lug nuts 70, along with the inclusion of extender 85,in FIG. 3 to accommodate for the thickness of lug nuts 70 and wheel 200as described. Thus, the use of extender 85 allows system 10 to beutilized when wheel 200 is connected to hub 12 while such extender isnot needed (i.e. due to lack of the thickness of the wheel and lug nuts)when wheel 200 is not mounted to hub 12.

In a further unillustrated example, cap 80 could be replaced by a cap ofa different axial dimension or thickness to accommodate a thickness ofthe wheel mounted on hub 12 as depicted in FIG. 3. In yet a furtherexample cap 80 could include a cavity configured to receive rods ordowels of various axial dimensions relative to the axis of shaft 14. Thevarious rods may be inserted into a cavity of such a cap depending onwhether endplay is to be measured with a wheel on a hub or without awheel mounted to such a hub. For example, a first rod of a firstdimension may be utilized when system 10 is utilized to measure endplaydirectly on a wheel hub. A rod having a second dimension longer than thefirst dimension may be utilized when endplay is to be measured on a hubhaving a wheel mounted. The difference in the dimension between thefirst rod and second rod may accommodate for the thickness added by thewheel mounted on the hub.

As described above, handle 40 may be grasped by a user and a force maybe applied thereto to move bearing 16 and hub 12 to a first positionfollowed by a “zeroing” of the probe and then movement to a secondposition. During the application of force to the first position and fromthe first position to the second position, handle 40 may be utilized torotate system 10 and thus hub 12 and bearing 16. This rotation insuresroller alignment of the bearing such that the measured endplay isaccurate for the circumference of hub 12 and bearing 16. Also, pressinglegs 55 are located on opposite sides of system 10 and are located about180° apart relative to the axis of shaft 14. The positioning of suchpressing legs substantially equally distant from one another andconnected to handle 40 via connecting legs 45 promotes an equidistantapplication of force to hub 12 and bearing 16 when a force is applied tohandle 40 described above such that twisting of the hub is minimized andan accurate measurement of endplay may be achieved and an off-centerloading of the bearing may be avoided. Handle 40 may also extendsubstantially perpendicularly relative to the axis of shaft 14 and mayextend through the axis to opposite sides of such axis as depicted inthe figures. In particular, handle 40 may connect to connecting legs 45,and connecting legs 45 may extend substantially parallel to the axis ofshaft 45 and pressing legs 50 may also extend substantially parallel tothe axis of shaft 45 such that connecting legs 50 may contact hub 12. Asdescribed above, pressing legs 50 may connect. to tabs 55 which extendsubstantially perpendicularly to pressing legs 50. It will be understoodby one skilled in the art that pressing legs 50 could connect to hub 12in any number of other ways while satisfying the objectives of theinvention.

Although aspects of the present invention were described above withrespect to their application to wheel hub assemblies, for example, truckwheel hub assemblies, it is understood that aspects of the presentinvention may be applied to any vehicle, machine, or component having atleast one bearing.

While several aspects of the present invention have been described anddepicted herein, alternative aspects may be effected by those skilled inthe art to accomplish the same objectives. Accordingly, it is intendedby the appended claims to cover all such alternative aspects as fallwithin the true spirit and scope of the invention.

1. A system for use in measuring an endplay of a bearing of a wheel hubassembly, the system comprising: a structure configured to contact anend of a shaft of the wheel hub assembly; a frame having a measurementprobe attached thereto, said probe configured to contact said structureto measure relative movement between a hub of the wheel hub assembly andsaid shaft to determine an endplay of a bearing of the hub assembly onthe shaft; said frame comprising a plurality of legs extending from saidframe to a hub of the hub assembly mounted on said shaft and coupled tosaid bearing to support said frame relative to the hub; a handleconnected to said frame; and said frame, said plurality of legs and saidhandle sufficiently rigid to allow a user to apply a force to saidhandle to move the hub in an axial direction relative to the shaft untila cessation of movement of the huh relative to the shaft.
 2. The systemof claim 1 wherein said frame comprises a plurality of cross membersconnected to said plurality of legs and having longitudinal dimensionsaligned substantially perpendicularly to the axis of the shaft.
 3. Thesystem of claim 1 wherein said frame is spaced from said structure whensaid structure is attached to the shaft to allow said frame to movetoward and away from said structure and to allow said probe to measuremovement of said frame relative to said structure.
 4. The system ofclaim 1 further comprising an extension attachable to said structurewhen a wheel is mounted on the shaft to couple said probe to saidstructure.
 5. The system of claim 1 wherein said probe is axiallyaligned with an axis of the shaft.
 6. The system of claim 1 furthercomprising an opening between two legs of said plurality of legs toallow a user to insert a tool into the opening such that the toolengages a nut holding said hub assembly on the shaft.
 7. The system ofclaim 1 wherein said structure comprises a wrenching surface to allowsaid structure to be tightened or loosened by a wrench.
 8. The system ofclaim 1 wherein said structure comprises a threaded surface configuredto engage a threaded surface of said shaft to connect said structure tosaid shaft.
 9. The system of claim 1 wherein said plurality of legs isconnectable to a plurality of wheel lugs of a wheel hub of the wheel hubassembly mounted on the shaft.
 10. The system of claim 1 wherein saidhandle extends a substantially equal distance on each side of the axisof the shaft.
 11. The system of claim 1 wherein said handle is connectedto said frame by a plurality of connecting legs, said handle located onan opposite side of said frame relative to said structure.
 12. A methodfor determining an endplay of a bearing of a wheel hub assembly mountedon a shaft, the method comprising; contacting a structure with an end ofthe shaft; connecting a plurality of legs of an endplay measuringapparatus to a hub of the hub assembly mounted on the shaft; connectinga measurement probe to a frame of the apparatus; the probe contactingthe structure; applying a force to a handle of the apparatus connectedto the frame and the plurality of legs to move the hub in a first axialdirection until a cessation of movement of the hub, the handle extendingsubstantially perpendicularly relative to an axis of the shaft andextending to opposite sides of the axis; determining a first measurementof the probe; applying a force on the handle in a second axial directionopposite to the first axial direction until a second cessation ofmovement of the hub; determining a second measurement of the probe afterthe second cessation of movement; and determining a movement of thestructure by the probe to determine an endplay of the bearing bycomparing the first measurement to the second measurement.
 13. Themethod of claim 12 further comprising turning the hub while the deviceis mounted to the huh to analyze roller alignment of the bearing. 14.The method of claim 12 wherein the applying the force comprises applyingthe force on the handle in a substantial axial direction relative to theaxis of the shaft to avoid off-center loading of the bearing.
 15. Themethod of claim 12 further comprising using a wrench to adjust atightness of a nut holding the hub assembly by extending the wrenchthrough an opening between two legs of the plurality of legs.
 16. Themethod of claim 12 further comprising attaching an extension to saidstructure when a wheel is mounted on the hub to couple the probe to thestructure.
 17. A system for use in measuring an endplay of a bearing ofa wheel hub assembly, the system comprising: a structure contacting anend of a shaft of a wheel hub assembly; a frame having a measurementprobe connected thereto, said probe contacting said structure andconfigured to measure relative movement of said structure to determinean endplay of a bearing of said hub assembly on said shaft; said framecomprising a plurality of legs extending from said frame to a hub ofsaid hub assembly mounted on said shaft and coupled to said bearing tosupport said frame relative to the hub; a handle connected to saidframe, said handle extending substantially perpendicularly relative toan axis of said shaft and extending to opposite sides of the axis; saidframe, said plurality of legs and said handle sufficiently rigid toallow a user to apply a force to said handle to move the hub in an axialdirection relative to said shaft until a cessation of movement of saidhub relative to said shaft; and said hub rotatable by said handle.
 18. Asystem for use in measuring an endplay of a bearing of a wheel hubassembly, the system comprising: a first structure configured to contactan end of a shaft of the wheel hub assembly; a frame having ameasurement probe attached thereto, said probe configured to contactsaid first structure and measure relative movement between said shaftand a wheel hub to determine an endplay of a bearing of the hub assemblyon said shaft; said frame comprising a second structure extending tosaid wheel hub of the hub assembly mounted on said shaft and coupled tosaid bearing to support said frame relative to the hub; a handleconnected to said frame, said handle extending substantiallyperpendicularly relative to an axis of the shaft and extending toopposite sides of the axis; and said frame sufficiently rigid to allow auser to apply a force to said handle to move the hub in an axialdirection relative to the shaft until a cessation of movement of the hubrelative to the shaft.